Combined drilling and tapping machine



G. W. IRWIN COMBINED DRILLING AND TAPPING MACHINE Feb. 6, 1940.

Filed Aug. 29, 1938 Mom;

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Patented Feb. 6, 1940 UNITED stares COMBINED DRILLING AND' TAPPIN GMACHINE George W. Irwin, Holland, Ohio, assignor to The i Toledo GeneralManufacturing Company,

Toledo, Ohio, a corporation of Ohio Application August 29, 1938, SerialNo. 227,296

7 claims.v (o1. 10--136) This invention relates to machines for drillingand tapping and an object is to produce a new and improved machine ofthis character which can be used either for drilling or for drilling andtapping without the use of troublesome or costly attachments or adaptersordinarily necessary to convert a drill press into a tapping machine.

Another object is to produce a'machine of the above character powered bya reversible motor which is controlled by a single switch rendering themachine operative for use as a drill press or as a tapping machine fordrilling screw threaded holes and in the latter case, the motor isautomatically reversed after the operation is completed, provision beingmade by a simple manual adjustment to render the machine suitable foreither type of work.

A further object is to produce a control for a machine of the abovecharacter having the new and improved features of construction,arrangement and operation hereinafter described.

For purposes of illustration but not of limita tion, an embodiment ofthe invention is shown on the accompanying drawing in which Figure 1 isa side elevation partly in section of a machine for drilling andtapping;

Figure 2 is an enlarged transverse sectional view on the line 2-2 ofFigure 1; and

Figure 3 is an enlarged fragmentary View of the switch box andassociated parts, the cover of the box being removed and also showingthe adjustable stop for actuating the switch after the tool hascompleted its operation.

The illustrated embodiment of the invention comprises a combined drillpress and tapping machine having a supporting standard ii] on the upperportion of which is mounted a reversible electric motor H on the shaftof which are a series of pulley wheels 12 from which an endless belt l3extends to a series of pulley wheels I4, these wheels being of varyingsizes as shown. The pulley wheels M are suitably fixed to a verticallydisposed driven shaft l5 which drives the tapping or drilling tool it,the drive mechanism being disposed within a quill H which in turn ismounted for vertical reciprocatory movements within a sleeve Ha which inturn slides vertically within a guide 13 that is suitably secured to thestandard. The sleeve Ha has rack teeth IS with which a pinion Z0 meshes,the latter having a. crank (not shown) for initially adjusting theposition of the parts vertically with respect. to the work. W. The quillI I has rack teeth llb with which a, pinion 2| meshes and by which the,tool It is advanced and retracted relative to the work W in theoperation of the machine. The mechanism for rotating the tool forms nopart of the present invention and maybe of any standard or well-knownconstruction so that further descripion thereof is not considerednecessary.

The pinion 2i is mountedon a transverse shaft 22 which hasan elongateopening 22a through' which a pin 23 secured to the pinion 2i projects toenable a slight amount of lost motion to take place between these parts.The shaft 22 is"dis-- 2i and operates normally to retract and hold thetool Hi to its uppermost or normal position. It will be noted that thecup 25 has an annular groove 28 into which extends a screw 29 forholding the cup 25 in its adjusted position.

The opposite end of the shaft 22 extends into a housing 30 to which acover plate Si is suitably attached. Disposed within the housing 30*is aswitch 32 which is suitably connected to and controls the reversiblemotor I I. The detail construction of the switch forms no part of thepresent invention and suflice it to say that the switch in cludes abutton 33 which, when depressed a very slight amount, operates toreverse the direction of rotation of the'motor H. Switches of thisgeneral character are well-known in the art and are frequently referredto as micro-switches. The switch 32 is supported on one end of anL-shaped arm 34 which is pivoted on a screw 35 secured to the housing30.

A set screw with asfiat end portion 38a and a knurled head 37 is carriedby the housing; 30. An adjusting screw 36b is threaded through the arm34 and bears against the end portion 36a; the arrangement being suchthat. an accurate adjusted position of the arm 34 may be secured by aslight rotation of the screw 36b.

Secured to the inner end of the shaftv 22 isa. pin 39 on which ismounted a disc Ml of leather or other suitable material which abutsagainst. the end of the shaft 22 and an eccentrically mounted metallicdisc M which bears against the leather washer. A coil spring vd2 on thepin 39 is interposed between the disc 4! and a nut 43 on the end of thepin and serves to hold the disc 4t frictionally in engagement. with the.washer: or

disc 40. The area of greater radius of the disc 4| is on the side of thepin 39 toward the switch 32 and formed in the edge portion of the disc4|, facing the switch button 33, is a notch in which seats one end of apin 44, the opposite end of which abuts against the switch button 33. Inthe region of the button 33 is a guide member 45 which receives the pin44 in a laterally elongate opening 46 which enables the pin 44 to rockin one direction or the other.

The disc 4| is formed with a notch 41 into which a pin 48, fixed to thehousing 30, extends thus limiting the rotating or turning movements ofthe disc 4| in either direction. Obviously only a slight turningmovement of the disc 4| is permitted but that movement is suflicient tocause depression of the switch button 33.

In operation, it will be understood that by turning the handle 26 in onedirection or the other, the pin 44 is moved slightly longitudinally asuiiicient amount to depress the switch button 33 thereby to reverse thedirection of rotation of the electric motor II. This is accomplished byimparting frictionally through the non-metallic washer or disc 40 aturning movement to the disc 4| and in the limited movement of thelatter, due to the eccentric mounting of the disc 4|, the pin 44 isrocked and during such rocking movement, a slight longitudinal movementis imparted to it. Thus, in turning the handle 26 to move the tool |6into operative engagement with the work W, the disc 4| will turn withthe shaft 22 thereby actuating the switch button 33 and cause the tooll6 to rotate in the proper direction. Then, if desired, the handle 26may be turned in the opposite direction which imparts movement to thedisc 4| in an opposite direction again depressing the switch button 33and again reversing the direction of rotation of the motor. Provision isalso made for automatically reversing the direction of rotation of themotor after the tool I6 has moved or advanced a predetermined distance.For that purpose, a screwthreaded rod 49 is carried by the quill H andpasses freely through a hole in a bracket 5s. A knurled nut 5| isadjustable on the rod 45. The quill advances toward the work W with thetool I6, and the nut 5| engages a spring arm 52 secured to the switcharm 34 and rocks the switch arm in a clockwise direction (Figure 3),thereby to force the switch button 33 against the pin 44 in ordertodepress the switch button and thus reverse the direction of rotation ofthe motor II. It is important to observe that when the switch arm 34 isrocked to cause reversal of the motor H, the rotation of the quill l! inthe reverse direction will thereupon reverse the direction of rotationof the pinion 2!. This, in turn, causes the shaft 22 to reverse itsmovement which, through the non-metallic washer 40, causes the disc 4|to rock in the opposite direction and thereby hold the pin 44 in thedesired position, thereby militating against the motor again reversingits direction of rotation before the tool l6 has been completelyretracted from the work W.

It is obvious that the position of the nut 5| may be adjusted so thatthe motor i will be automatically reversed in the manner describedsubstantially when tapping has been completed and of course the reversalof the direction of rotation of the tool I6 is necessary when themachine is used for tapping purposes in order that the tool IS canunscrew itself from the work.

When the machine is used solely as a drill press, reversal of thedirection of rotation of the tool I6 is not desired and to set themachine so that the motor I will rotate only in one direction, theknurled head 3? of the screw 36 is turned to move the flat end 38a awayfrom the screw 3% to allow the switch 32 to swing by gravity in acounter clockwise direction and thus move the button 33 away from thepin 44. It will be apparent that in this position, the pin 44 can notdepress the button so that the machine will op-- erate continuously inone direction in the usual manner of a drill press.

It is to be understood that numerous changes in details of construction,arrangement and operation may be effected without departing from thespirit of the invention especially as defined in the appended claims.

What I claim is:

1. In a machine of the class described having a rotary tool mounted formovement toward and away from the work, a reversible motor operativelyconnected to the tool, a manually operated rotatable shaft operativelyconnected to advance the tool, a switch operable when actuated toreverse the operation of the motor, a rotatable disc associated with andactuated by said shaft and disposed in eccentric relation thereto, meansfor limiting the rotative movements of said disc in opposite directions,and an operative connection between said disc and switch enablingactuation of the latter upon turning of said disc.

2. In a machine of the class described having a rotary tool mounted formovement toward and away from the work, a reversible motor operativelyconnected to the tool, a switch operable when actuated to reverse theoperation of the motor, a rotatable shaft operatively connected toadvance the tool, a rotatable member frictionally associated with andactuated by said shaft and arranged eccentrically thereto, stop meansfor limiting the turning movement of said member in opposite directions,and an operative connection between said member in the region of thegreater radius thereof and said switch enabling actuation of the latterupon turning of said member in either direction.

3. In a machine of the class described having a rotary tool mounted formovement toward and away from the work, a reversible motor operativelyconnected to the tool, a switch operable when actuated to reverse theoperation of the motor and including a depressible button, a manuallyoperated rotatable shaft operatively connected to advance the tool, arotatable disc adjacent one end of said shaft and disposed eccentricallythereto, spring means urging said disc toward the shaft,

a non-metallic disc interposed between said shaft and rotatable disc,stop means enabling limited turning movements of said rotatable disc inopposite directions, a pin loosely fitting at one end in a notch in saidrotatable disc in the region of its greater radius and having itsopposite end in abutting relation to said switch button, and means tohold said pin in position and enable limited rocking movements.

4. In a machine of the class described having a rotary tool mounted formovement toward and away from the work, a reversible motor operativelyconnected to the tool, a switch operable when actuated to reverse theoperation of the motor and including a depressible button, a manuallyoperated rotatable shaft operatively connected to advance the tool, arotatable disc adjacent one end of said shaft and disposed ec-'centrically thereto, spring means urging said disc toward the shaft, aIlOIl-lllEl-hlllCdlSC interposed between said shaft and rotatable disc,stop means enabling limited turning movements of said rotatable disc inopposite directions, a" pin loosely fitting at one end in a notch insaid rotatable disc in the region of its greater radius and having itsopposite end in abutting relation to said switch button, means to holdsaid pin in position and enable limited rocking movements, a pivotalmounting for said switch including an outwardly extending arm, andadjustable means movable with said tool engageable with said arm therebyto rock said switch and cause said pin to depress the button to causereversal of the motor upon predetermined movement of the tool.

5. In a machine of the class described having a rotary tool mounted formovement toward and away from the work, a reversible motor operativelyconnected to the tool, a switch operable when actuated to reverse theoperation of the motor, a rotatable shaft operatively connected toadvance the tool, a rotatable member frictionally associated with andactuated by said shaft and arranged eccentrically thereto, stop meansfor limiting the turning movement of saidv member in oppositedirections, an operative connection between said member in the region ofthe greater radius thereof and said switch enabling actuation of thelatter upon turning of said member in either direction, and meansresponsive to predetermined advancing movement of the tool to operatesaid switch to cause reversal of the motor.

6. In a machine of the class described having a rotary tool mounted formovement toward and away from the work, a reversible motor opera,-tively connected to the tool, a switch operable when actuated to reversethe operation of the motor, a rotatable shaft operatively connected toadvance thetool, a rotatable member frictionally associated with andactuated by said shaft and arranged eccentrically thereto, stop meansfor limiting the turning movement of said member in opposite directions,an operative connection between said member and said switch enablingactuation of the latter upon turning of said memher in either direction,and means responsive to predetermined advancing movement of the tool tocause reversal of the motor.

'7. In a machine of the class described having a rotary tool mounted formovement toward and away. from the work, a reversible motor operativelyconnected to the tool, a switch operable when actuated to reverse theoperation of the motor, a rotatable shaft operatively connected to-GEORGE W. IRWIN.

